Senior Vice President of Marketing David Thompson took a break from party-planning to give me a quick demo of the app. He says one of the main goals is simplicity, which is one reason why BFF is launching as a standalone product, rather than an addition to the existing Ustream iPhone app. To start making a video, you just enter a short description, a privacy setting (whether you want it to be viewable to everyone, just to your Facebook friends, or entirely private), and choose filter.

Then video is posted on your Facebook Timeline, and here’s the cool part — your friends can start watching live footage, directly from Facebook. When people leave comments or “like” your video, you get notified as you’re filming within the app. Once you’re done filming, the video switches from a livestream to a recording.

Cell reception in the TechCrunch office is terrible, so Thompson demonstrated the app for me over WiFi, and the footage was, indeed, streaming live to Facebook with a delay of only a few seconds. Apparently the BFF app does a bandwidth check before you begin streaming. If you don’t have enough bandwidth, the app just records the footage instead, and then immediately uploads it once you’re connected again.

Thompson counters that only Ustream has built the technical infrastructure to support live mobile video of this quality. He also argues that there are many moments that are just so much more powerful when they’re live. For example, he shared his baby’s first steps through the BFF app — if you’re part of the family, it’s nice to watch a video of the first steps, but if you get to see those first steps as they happen, “that’s something you’ll never forget.” The same argument could apply to things like sports, concerts, or really any special events.

The app should be available “very soon,” Thompson says. Also coming in that promising-but-vague timeframe: The ability to view live video not just on Facebook’s desktop site, but on mobile too.